gps logger 10hz

Question

Hi my name is Leonardo and I`m new in this and I was wondering if anyone can help me with a little problem I have with my gps logger. I`m using a venus gps, an arduino uno rev3, a mpu6050 and a sd shield. The gps logs perfectly when it is set to 1hz but when puting it at 10hz, strange simbols appears inthe gps data lines in the file logged. It is not allways and it is only in the gps data part, the mpu6050 is ok. Does anyone knows why this could be? The file is attached, notice that only the gps part has those strange characters 
 Attachments: LOGGER00.CSV.zip

nabhi · Answer

It is the problem with the baud rate. You see the total record length. Calculate the number of bits in a full record. See what is the baud rate set. Calculate whether 10Hz is ok or not You should be able to read the full record in 100ms. If u try to update faster than the read of port, then the garbage comes in.

shabaz · Answer

The fact that it is higher than 4800 baud rules out this theory. 38400 should be more than sufficient. It could be that the microcontroller is running with a non-crystal (i.e. non-accurate) oscillator, and maybe the problem was still there at 1Hz, but occurred less frequently, since most of your .csv file seems to contain correct data, with few rows containing incorrect data. At 1Hz, were you using 38400 baud too, or a lower value? You probably need to post an image or link to the arduino microcontroller board that you're using. Also, I don't know the implementation of the UART API in arduino; maybe you're overrunning a buffer due to the higher bitrate. Unfortunately, someone more experienced in Arduino may need to respond to you to help find the problem.